In an update published today to Google Play Store, Facebook app for Android has been enhanced for faster opening and viewing of photos. There is also an option to share your friends' stories to timelines, pages and groups. The last added feature is the ability to send voice messages within the app. Unless my memory is failing me, It seems to me that the voice message feature was always there. Checkout the notification center to download the update or head over to Google Play Store to download the app.